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    <title>Document</title>
    <script>
        // filter 筛选数组
        // var arr1 = [12, 66, 4, 88, 3, 7];
        // var newArr1 = arr1.filter(function (value, index) {
        //     return value >= 20;
        // })
        // console.log(newArr1);
        // var arr2 = [12, 66, 4, 88, 3, 7, 12, 66, 88];
        // var newArr2 = arr2.filter(function (value, index) {
        //     return value % 2 === 0;
        // });
        // console.log(newArr2)
        var arr = [12, 66, 4, 88, 3, 7, 12, 66, 88];
        var newArr = arr.filter(function (value, index) {
            // return value >= 20;
            return value % 2 === 0;
        });
        console.log(newArr);
        // 去重
        var newArr1 = arr.filter(function (value, index) {
            return arr.indexOf(value) == index;
        })
        console.log(newArr1)
    </script>
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